Carbon-steel disintegrating composition and method

ABSTRACT

THE METAL-DISINTEGRATING COMPOSITION CONSIST OF A MIXTURE IN WATER OF SULPHURIC ACID, NITRIC ACID, ACETIC ACID AND SODIUM CHLORIDE. THE PROPORTIONS OF INGREDIENTS ARE SUCH THAT THE COMPOSTION WILL DISINTEGRATE STEELS, SUCH AS HIGH SPEED STEEL AND CARBON STEEL, COMMONLY EMPLOYED FOR THE MANUFACTURE OF MACHINE TOOLS. THE COMPOSITION WILL NOT CAUSE DETERIORATION OF MANY OF THE METALS WHICH ARE COMMONLY UTILIZED FOR PARTS WHICH ARE WORKED BY MACHINE TOOLS. THE METAL-DISINTERGRATING METHOD COMPRISES THE APPLICATION OF THE COMPOSITION TO THE STEEL, UNDER A WIDE RANGE OF TEMPERATURE CONDITIONS.

United States Patent O 3,565,708 CARBON-STEEL DISINTEGRATING COMPOSITION AND METHOD Jack C. Ellis, 2298 S. 1st St., San Jose, Calif. 95112 No Drawing. Filed Mar. 8, 1968, Ser. No. 711,508 Int. Cl. C23f 1/00; C23g 1/20 US. Cl. 156-18 9 Claims ABSTRACT OF THE DISCLOSURE The metal-disintegrating composition consists of a mixture in water of sulphuric acid, nitric acid, acetic acid and sodium chloride. The proportions of ingredients are such that the composition will disintegrate steels, such as high speed steel and carbon steel, commonly employed for the manufacture of machine tools. The composition will not cause deterioration of many of the metals which are commonly utilized for parts which are worked by machine tools. The metal-disintegrating method comprises the application of the composition to the steel, under a wide range of temperature conditions.

BACKGROUND OF THE INVENTION The present invention relates to the disintegration of metals, and more particularly to a composition for, and a method of, disintegrating steels such as high speed steel and carbon steel, commonly employed for the manufacture of machine tools.

A problem has existed in the prior art, with respect to the need for a method of disintegrating the highly heatresistant types of steel, such as high speed steel and carbon steel, which find particular use in the manufacture of machine tools. Generally, the carbon steel would be of a high carbon steel. A tool, such as a drill or tap, constructed of one of such types of steel, may ocasionally break during use. Fragments of the broken tool may then lodge in a hole being tapped or drilled, or in some other position from which removal is difficult. Metal-disintegrating compositions, such as have been known in the prior art, have presented numerous disadvantages with respect to their possible use for the removal of the tool fragments. Some of the known metal-disintegrating compositions have not been suitable for the disintegration of the types of steels of which the machine tools are constructed. Other of the known compositions, although suitable for disintegrating the tool fragments, would also disintegrate the metal part which was being worked by the machine too. Some of the known metal-disintegrating compositions, although not of a type which would disintegrate the metal part being worked, would cause serious pitting or discoloration of the latter.

SUMMARY OF THE INVENTION A metal-disintegrating composition, consisting of a mixture of the following ingredients, each ingredient being present in the mixture in an approximate range of percentage concentration by volume as set forth below:

Percent Sulphuric acid 10-12 Nitric acid 27-33 Acetic acid -6 Sodium chloride .5-.7-

Water 47-58 The above composition is applied at a temperature within the approximate range of 32 F. to 180 F. to steels having a high heat resistance, for the disintegration of such steels. In the exemplary embodiment, the temperature range is between F. and F. The sulphuric acid, in the preferred embodiment, is a solution having a concentration of 66 B. The nitric acid, in the exemplary embodiment, has a concentration of 40 B. In the exemplary embodiment, the acetic acid is of the glacial acetic acid of photographic quality. In the exemplary embodiment, the water is distilled.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION The metal-disintegrating composition of the invention is formulated of a mixture of the following ingredients, each ingredient being present in the mixture within a range of percentage concentration by volume as set forth:

Percent Sulphuric acid 66 B' 10-12 Nitric acid 40 B 27-33 Glacial acetic acid photographic quality 5-6 Sodium chloride .54-.66 Distilled water 47-58 In admixing the above ingredients, the water (preferably distilled water) is initially measured into a suitable container. The nitric acid is then added to the water while mixing. Similarly added to the water thereafter, and, in turn, are the acetic acid, the sulphuric acid, and the sodium chloride.

The above composition is suitable for the disintegration of steels having a high heat resistance, such as high speed steel and hard carbon steel, throughout an approximate temperature range of from 32 F. to 180 F. Preferably, the temperature range is from 100 F. to 180 F. The

. disintegration of such machine tool steels results from an oxidation of the alloyed elements. The disintegration is sufficiently rapid for practical commercial purposes. At the same time, and as a consequence of the presence of the sodium chloride, the disintegrating action is sustained despite the formation of oxidation products. The higher the temperature employed, the faster is the disintegrating action.

Although the composition of the invention will disintegrate high speed steel and carbon steel which are commonly employed for machine tool construction, such composition will have little effect upon many of the metals which are commonly worked by machine tools. Thus, the composition of the invention will not cause deterioration of such stainless steels as AISI Types 302, 303, 304, 316, 321, 347, 410, 416, 430; and the stainless steels of the group 17-4. The composition of the invention will like wise not cause deterioration of any of the grades of Inconel (trademark). The composition of the invention will cause only a slight deterioration, such as a dulling of the surface, of most aluminum alloys.

The composition of the invention will cause substantial deterioration, in various degrees, when applied to magnesium, certain forms of titanium, nickel alloys, molybdenum, mu-metal copper or brass.

The composition of the invention may be employed, for example, for the removal of fragments of a broken machine tool constructed of high speed steel or high carbon steel, from a hole in a machined metal part constructed of one of the above-mentioned metals which is substantially resistant to deterioration. If the machined part is comparatively small, it may be completely submerged in the composition, for the disintegration of the fragments. If the machined part is comparatively large, the composition can be introduced into the hole from which the fragments must be removed. As a convenient method of introducing the composition, a small dam of a material such as clay, can be formed at the surface of the machined part and surrounding the opening of the hole. The composition can then be poured into the hole, with suflicient composition being retained by the dam to maintain good Working action. Similarly, if the hole is drilled through the machine part, the inner end of the hole may be closed off with a material, such as clay, prior to introduction of the composition.

If the machined part is large, it may be heated, so as to increase the speed of the disintegrating action.

After the disintegration of the tool fragment, the surfaces of the machined part which have been contacted by the composition of the invention are preferably rinsed with water. Such surfaces are thereafter preferably rinsed with an acid neutralizer, such as, e.g. a strong solution of ammonia and water or a solution of baking soda and water, for neutralization of the acids in the composition.

EXAMPLE .1

Percent by volume Sulphuric acid 66 B' 11 Nitric acid 40 B 30 Glacial acetic acid photographic quality 5.5 Sodium chloride .6 Distilled water 52.5

EXAMPLE 2 Ounces by volume Sulphuric acid 66 B 7.2 Nitric acid 40 B 19.3

Glacial acetic acid photographic quality 3.6 Sodium chloride (215 grains by weight) .39 Distilled water 33.8

Percent Sulphuric acid 10-12 Nitric acid 27-33 Acetic acid 5-6 Sodium chloride .54-.66 Water 47-58 wherein said sulphuric acid and said nitric acid disintegrate said steel, said acetic acid reduces the size of gas bubbles formed by said sulphuric and nitric acids disintegrating said steel, and said sodium chloride reduces smut or scale formation on said disintegrating steel.

2. A metal-disintegrating composition in accordance with claim 1, in which each ingredient present in the mixture in an approximate percentage concentration by volume as follows:

Percent Sulphuric acid 11 Nitric acid 30 Acetic acid 5.5 Sodium chloride .54.66

Water 52.5

3. The method of disintegrating a steel having a high heat resistance, or a hard carbon steel or a high speed steel, which method comprises the step of applying to said steel a composition of matter consisting of the following ingredients, each ingredient being present in the mixture within an approximate range of percentage concentration by volume as set forth:

Percent Sulphuric acid 10-12 Nitric acid 27-33 Acetic acid 5-6 Sodium chloride .54.66

Water 47-58 in which said sulphuric acid and said nitric acid disintegrate said steel, said acetic acid reduces the size of gas bubbles formed by said sulphuric acid and nitric acid disintegrating said steel, and said sodium chloride reduces smut or scale formation on said disintegrating steel, said composition being applied to said steel at a temperature within the approximate range of 30 F. to 180 F.

4. A method in accordance with claim 3, in which said temperature of application is approximately F.- F.

5. A metal-disintegrating composition as claimed in claim 1 wherein the sulphuric acid has a concentration of 66 B-.

6. A metal-disintegrating composition as claimed claim 5 wherein the nitric acid has a concentration 40 B6.

7. A metal-disintegrating composition as claimed claim 6 wherein the acetic acid is a glacial acetic acid.

8. A metal-disintegrating composition as claimed claim 6 wherein the water is distilled water.

in of 9. A metal-disintegrating composition as claimed in claim 7 wherein the water is distilled water.

References Cited UNITED STATES PATENTS 2,337,062 12/1943 Page 148-8 2,411,532 11/1946 Escotfery 15618X 2,584,317 2/1952 Aller 1-56-1'8X 3,010,854 11/ 1961 Satterfield 156-1 8X J. STEINBERG, Primary Examiner 

